The present invention relates generally to navigational devices, and in particular to identification of thoroughfares.
Route planning devices are well known in the field of navigational instruments. The method of route planning implemented by known prior art systems depends on the capabilities of system resources, such as processor speed and the amount and speed of memory. As increased system capability also increases system cost, the method of route planning implemented by a navigation device is a function of overall system cost.
One feature of increased system capability cost involves the labeling of thoroughfares with a best name, or a most well-known name. Thoroughfare names are either shielded or not shielded. A shielded thoroughfare name is one that appears on signs along thoroughfares inside of a symbol rather than merely being spelled out. Examples of shielded name includes US1, I270, or State 91. A non-shielded name is a name for a thoroughfare that is not typically displayed in a symbol on signs, such as xe2x80x9cJeff Davis Highwayxe2x80x9d or xe2x80x9cJack Nicklaus Freeway.xe2x80x9d Some thoroughfares have multiple names, some of which may be shielded and some of which may be non-shielded name, for example, xe2x80x9cJeff Davis Highwayxe2x80x9d in Virginia is a non-shielded name for the same thoroughfare whose shielded name is xe2x80x9cUS1.xe2x80x9d
In general, thoroughfares are better known by their non-shielded name, except for interstate thoroughfares. For example, highway US1 is more well known by the non-shielded name of xe2x80x9cJeff Davis Highway.xe2x80x9d In contrast, the I635 interstate beltway around Kansas City, Kansas is not very well-known by its non-shielded name of the xe2x80x9cHarry S. Darbyxe2x80x9d freeway.
Furthermore, conventional cartographic displays in navigational instruments frequently do not display the well-known non-shielded name of a thoroughfare. For example, conventional systems display the name xe2x80x9cUS1xe2x80x9d on the display as a label for the thoroughfare that is better-known as the xe2x80x9cJeff Davis Highway.xe2x80x9d
The frequent use of less-than-well-known thoroughfare names creates problems for the users of the cartographic data from navigation devices. More frequently than not, thoroughfare signs identify thoroughfares using the better-known names of the thoroughfares. As a result, the names on the thoroughfare signs can be different than the name provided by the navigation device. When the names are different, the user may not correctly identify the thoroughfare while in route, and may travel past, or miss the intended course of navigation.
Additionally, thoroughfare names often have a suffix, such as xe2x80x9cbusinessxe2x80x9d or xe2x80x9calternate.xe2x80x9d For example, xe2x80x9cI-44 businessxe2x80x9d in Rolla, Mo., designates a portion or spur of I-44 that services a business district of a city that is also known by the non-shielded name of xe2x80x9cUS63.xe2x80x9d An exception to the above rule in which interstate thoroughfares (xe2x80x9cinterstatesxe2x80x9d) are most well-known by the shielded name is that interstates with a suffix are better known by their non-shielded name. Therefore, xe2x80x9cI-44 businessxe2x80x9d is better-known as xe2x80x9cUS63.xe2x80x9d
In summary, conventional systems often communicate a label to a navigational device with a lesser-known name, or a nearly unknown name. Furthermore, conventional systems do not necessarily label a thoroughfare on a cartographic display of a navigational device with a better-known, or the best-known, name of the thoroughfare. Therefore, there exists a need for systems, methods, data structures, and apparatus adapted to communicate a label of a thoroughfare through an output of a navigational device with a better-known name, a well-known name, or the best-known name, of the thoroughfare.
The above mentioned problems of navigational devices are addressed by the present invention and will be understood by reading and studying the following specification. Systems and methods are provided to allow a better-known name, a well-known name, or the best-known name, to identify thoroughfares in cartographic data. The systems and methods of the present invention offer an improved navigational device which has a cartographic display with thoroughfare labels that correspond to the well-known name of the thoroughfare, which in turn, more accurately, efficiently, and understandably assists in navigation.
In some embodiments, a well-known name, a better-known name, and/or a most appropriate name in a given context of a thoroughfare is selected as the label name of the thoroughfare in cartographic data. One example of a well-known name is a non-shielded name. Where the thoroughfare is not an interstate, the first non-shielded thoroughfare name in a set of thoroughfare labels is identified and/or selected as the name of the thoroughfare. The same holds true if the thoroughfare is an interstate and the name for the interstate has a suffix.
In another embodiment, an electronic navigational aid device that identifies a name of a thoroughfare includes a memory and a processor. The memory includes a list of one or more names of the thoroughfare, and the shield types, if any, of the names of the thoroughfare. The processor is adapted to communicate with the memory. The processor obtains the list of names of the thoroughfare, and the shield types, if any, of the name(s) of the thoroughfare. The most well-known name of the thoroughfare is selected from the list for labeling the thoroughfare.
The present invention has the advantage of using a better-known name for a thoroughfare in cartographic data. This is helpful to a human user of the cartographic data when the cartographic data is used or relied upon by the user in navigating thoroughfares.